Mud flaps on trucks are subject to compliance standards which are enforced by the regulating authority in the relevant jurisdiction. To applicant's knowledge, several jurisdictions a so-called one third rule is applied in regulating the clearance between the ground and the bottom of the mud flaps; namely, that the clearance cannot exceed one third of the distance between the mudflap and the axle centre of the nearest axle to the mud flap. Thus, for example, if the horizontal distance between the mud flap when hanging free and the axle centre of the nearest axle to the mud flap is 24 inches, the lowermost edge of the mud flap can be no more than eight inches above the ground. This amount of clearance can cause problems when a dump truck is backing up to dump its load.
As stated by Nickels in his U.S. Pat. No. 6,158,775 which issued Dec. 12, 2000, vehicles which require mud flaps, such as trucks and trailers, frequently have the mud flaps torn from their mounting brackets during normal operation of the vehicle, and in particular, the majority of the mud flaps are torn off when the vehicle is backing up or when dumping a load at the back of the vehicle. Nickels gives one example of when trucks or trailers are backing up over rough terrain, such as stone, loose dirt, heavy snow/ice, curbs or other similar obstacles, stating that the mud flaps are often caught under the tires of the vehicle, which tears the mud flap from the mud flap's mounting bracket. Nickels states that in some cases the weight of the vehicle backing over mud flap will pull the flap brackets, chrome, and other mounting devices from the vehicle. It has been applicant's and Nickels' experience that owners and operators of vehicles which require mud flaps are frustrated by the time and expense required to replace mud flaps which are damaged or torn from their mounting brackets; that is, even though the mud flaps are not in themselves expensive, the lost operating time for the vehicle and the additional manpower expense required to install new mud flaps can become a significant operating expense for the owner/operator. Lack of a mud flap may also attract a fine or result in a shut-down of operations.
Also, in the prior art applicant is aware of United States published patent application publication no. 2003/0184078 published Oct. 2, 2003 for the Mud Flap Lifting System of Grable. In Grable, when the user wishes to retract assemblies 14 the user actuates valve 36 causing activator 22 to extend rod 24 rearwardly to a second position. To lower the mud flaps it is assumed that the user would have to reverse the procedure. If the user forgets to activate valve 36 to raise the flaps the flaps may get damaged. If the user forgets to lower the flaps, the user may be fined for short mud flaps and no brake or signal lights showing if the lights are mounted in the top portion of the flaps as shown. If the user backs the vehicle up a hill, raises the flaps and dumps the load with the lower flap 30 hanging down in a vertical position and then moves ahead and lowers the box before lowering the flaps, the flaps may get damaged or the tires may be damaged.
In the prior art applicant is further aware of U.S. Pat. No. 3,203,710 which issued Aug. 31, 1965, to Harting Jr. for a Mud Flap Retractor. Harting Jr. notes that “the additional operating means are too often forgotten by the truck driver.” (emphasis added).
Harting Jr. does not mention an anti-sail cable. All he provides is a cable for lifting the flaps after the box is raised. In applicant's view Harting Jr's. cable would not work as an anti-sail device. His cable lifts the flaps by bending them inward. If the flaps may be bent in, then they would also bend out and raise the bottom of the flap up because of the wind while travelling thereby causing the flaps to sail backwards. Harting Jr. would have to for example have a stiffener rod in the center of the flaps for the cable to pass through, however that would not work using a flexible flap. Harting Jr. would have worn out the cable #8 and guides #16 and 17 in a short time without the use of pulleys. His flaps could get caught in the up position if the frayed cable got caught in the worn guides by only using gravity to lower the flaps. In the present invention, the flaps lower by air pressure through the air cylinder.
If Harting Jr. or Grable would have had legal length flaps, when they backed a loaded gravel truck up the flaps would have hit an obstruction and stopped. The tires would have ripped or torn the flaps off.
In the prior art, and apart from the Nickels U.S. Pat. No. 6,158,775, applicant also aware of U.S. Pat. No. 3,165,360, which issued Jan. 12, 1965 to Saxton et al for an Automatic Mud Flap Retractor for Dump Truck Vehicles; U.S. Pat. No. 3,248,126, which issued Jun. 1, 1964 to Saxton et al for Mud Flap Retractors; U.S. Pat. No. 3,582,109, which issued Jun. 1, 1971 to Moore for a Mud Flap Retraction Apparatus; U.S. Pat. No. 3,806,196 which issued Apr. 23, 1974 to Cole et al for an Automatic Mud Flap Retractor for Rear-Dumping Trucks; U.S. Pat. No. 6,139,062, which issued Oct. 31, 2000 to Meyer for a Mud Flap Lifter; U.S. Pat. No. 6,402,200 which issued Jun. 11, 2002 to Myers for an Apparatus and Method for Moving Mud Flaps to a Protected Position; U.S. Pat. No. 6,623,038 which issued Sep. 23, 2003, to Heem for an Automatic Lifting Mud Flap Assembly; United States Publication No. US2004/0164539 which published Aug. 26, 2004 to Bernard for a Mud Flap Lifter System; U.S. Pat. No. 6,799,808 which issued Oct. 5, 2004 to Walters for a Dump Truck Automatic Mud Flap Retractor System; and U.S. Pat. No. 7,021,665 which issued Apr. 4, 2006 to Keller for a Mud Flap Saver Apparatus.